It is known that in the course of a flight, violent turbulence related to vertical wind gusts can cause at the aircraft level:                significant variations in vertical acceleration which, when they are negative, may injure passengers of the aircraft;        a significant swerve of the aircraft in terms of altitude, thereby increasing the risk of collision with another aircraft;        spikes in the lift on the airfoil, which test the load limit of the latter; and        roll moments, as well as lateral accelerations, which may also injure passengers of the aircraft.        
Two types of atmospheric turbulence are generally the cause of the disruption experienced by an aircraft, namely:                clear sky turbulence, of CAT (“Clear Air Turbulence”) type, which represents wind shears which often occur without any visible manifestation, generally above 15 000 feet (about 4500 meters). This clear sky turbulence, which is of non-convective type, usually appears near the tropopause, especially above mountains and especially in winter. Such turbulence presents a natural risk in flight and can bring about injuries to the passengers and flying personnel under certain particularly severe conditions. Moreover, such turbulence gives rise to additional fuel consumption (avoidance of the turbulence zone) and contributes to the fatigue of the aircraft and pilots; and        convective turbulence which is often visible through the presence of clouds. Severe convective turbulence appears in fairly humid regions, so that a radar can generally detect it. So, most of the time, this phenomenon can be avoided by aircraft. However, it may happen that pilots are surprised or that they do not have time to evade a zone of convective turbulence. The severest turbulence appears in storm clouds, with ascending and descending currents that may reach several tens of meters per second. This convective turbulence is very localized and less extensive than clear sky turbulence.        
Often, the above phenomena which are localized surprise both the crew of the aircraft and the embedded piloting systems, which do not have time to perform the appropriate maneuvers to attenuate the effects thereof, especially lateral effects, which result therefrom at the aircraft level.
Patent applications FR-05 10341 and WO-2007/042652 disclose a device for attenuating on an aircraft the effects of a vertical turbulence encountered by this aircraft in the course of a flight.